Instalab ResearchClinical studies consistently demonstrate that individuals with lower triglyceride levels experience reduced risk of both cardiovascular disease and overall mortality. In the Copenhagen City Heart Study, non-fasting triglycerides below 1 mmol/L (about 89 mg/dL) were associated with a 41% reduction in all-cause mortality compared with individuals in the high triglyceride range of 3.00–4.99 mmol/L. These findings were statistically significant and robust after adjusting for confounders.
Genetic studies provide additional evidence for a causal role. Variants in lipoprotein lipase that result in life-long reductions in triglyceride levels were associated with nearly 50% lower risk of all-cause mortality. This genetic evidence supports the interpretation that low triglycerides are not just markers of good health, but may actively contribute to improved survival.
The association between low triglycerides and extended lifespan appears to follow a dose-response pattern. In the same Copenhagen study, individuals with triglyceride levels between 1.00 and 1.99 mmol/L (roughly 89–176 mg/dL) still had a 26% lower risk of all-cause mortality compared to those in the highest ranges. The lowest category showed the strongest protective effect, suggesting that modest reductions in triglycerides translate into measurable improvements in longevity.
This relationship remained significant across multiple analyses, which strengthens the conclusion that maintaining low triglycerides supports longer life expectancy.
Although moderately low triglycerides are beneficial, values that fall below approximately 40 mg/dL can raise concern. Extremely low levels are sometimes caused by malnutrition, malabsorption, hyperthyroidism, or rare lipid disorders such as abetalipoproteinemia and hypobetalipoproteinemia. In these contexts, low triglycerides reflect underlying pathology rather than protection.
Studies in patients with heart failure further demonstrate that the relationship between triglycerides and survival may be U-shaped. Both high and very low triglyceride levels were linked with higher mortality risk, particularly in frail or malnourished patients. This indicates that in vulnerable populations, triglyceride levels may be a proxy for nutritional or metabolic reserves rather than purely a cardiovascular risk factor.
Triglycerides are only one component of the broader lipid profile. In some cases, low triglycerides can appear alongside elevated low-density lipoprotein (LDL) cholesterol, such as in familial hypercholesterolemia. In these individuals, cardiovascular risk remains high despite favorable triglyceride levels. Conversely, when low triglycerides occur with low remnant cholesterol and stable LDL levels, the overall risk profile is generally improved.
Comprehensive lipid assessment is therefore essential, since triglyceride values alone do not capture the full picture of metabolic or cardiovascular health.
The protective effects of low triglycerides likely arise from reduced levels of remnant lipoproteins, which are strongly atherogenic. Mendelian randomization studies show that genetically lower triglyceride levels correspond to lower remnant cholesterol and substantially reduced risk of cardiovascular mortality. While clinical trials of triglyceride-lowering drugs have shown mixed results, the genetic data support a causal link between low triglycerides and improved survival.
The discrepancy may be explained by the fact that genetic variation provides life-long reduction in triglycerides, whereas pharmacological interventions are often introduced later in life and may not capture the full benefit of early risk modification.
For most individuals, triglyceride levels in the range of 50–90 mg/dL are considered optimal and associated with better cardiovascular and longevity outcomes. Levels below 40 mg/dL, particularly if persistent, should prompt clinicians to investigate possible underlying causes such as endocrine disorders, malnutrition, or malabsorptive diseases. In patients with advanced heart failure or systemic illness, very low triglycerides may reflect declining metabolic reserves and portend worse outcomes.
In clinical practice, low triglycerides in otherwise healthy individuals are typically reassuring. However, in symptomatic or chronically ill patients, they should be evaluated in context, alongside LDL, HDL, remnant cholesterol, and inflammatory markers.
